Diesel engine starting fluid



Patented Nov. 25, 1947 r UNITED srAr-Es PATENT orrice DIESEL ENGINE STARTING FLUID R. Wayne Goodale, Berkeley, Calii'., assignor, by to California Research Corporation, San Francisco, Calif., a corporamesne assignments,

tion of Delaware No Drawing. Application May 1, 1944,

Serial No. 533,649

Claims. 1

In Diesel engine operation, a liquid fuel is injected into a combustion chamber and ignited by compression and, since the ignition temperature of the fuel is reached, during normal and continued operation in any certain engine and with any certain fuel, as a result of the combined effect of compression and the temperature of engine parts, difilculty is often encountered in attempting to initiate compression ignition in a cold motor with a fuel satisfactorily adapted for thus running. In meeting such difficulties, externally derived heat is sometimes applied'to significant engine parts, to raise. their temperature, .and fuels of relatively low ignition temperatures are often employed for such time as is required to start ignition and allow engine temperatures to rise; sometimes, but by no means invariably, the addition to the liquid fuel of a so-called primer, normally effective in decreasing the ignition delay period of the fuel during continuous engine operation, will act to assist in the cold starting of the engine. As is well known, cold startingdimculties are so real and serious that 'Diesel engines are often allowed to run at idling speed for hours and frequently overnight, to maintain ignition temperatures, rather than attempt the initiation of compression ignition in an engine cooled to atmospheric temperature. These difliculties are immensely magnified in equipment employed in northern climates or in adverse weather conditions when, for example, the temperature may drop to as low as 'F. and below.

The invention comprises the introduction of a particularly characterized auxiliary combustible fluid or fuel into the air stream entering the combustion chambers of a Diesel or compression ignition engine, in gaseous or vaporous or in finely divided liquid form, in fairly high concentration. Such introduction to the air stream, as through the air intake manifold of the engine, permits-the presence of the auxiliary cold starting agents during the whole compression stroke of the motor rather than merely concomitant with the entry of the liquid hydrocarbon fuel normally injected into the combustion chambers at a point approaching top dead center.

It is accordingly an object of the invention to disclose and provide cold starting fluids capable of initiating or accelerating the starting of Diesel engines at low temperatures and to provide methods of accomplishing such starting by the intro- 'duction of the said 'iluids into the air intake streams of the engines. It is a, further object of the invention to disclose and provide fluids or auxiliary combustion-initiating agents effective in such operations. Other objects and numerous advantages of the invention will be apparent to those skilled in the art to which it appertains.

The auxiliary combustible or cold starting fluid of the invention comprises a. major proportion of a volatile alkyl ether of low molecular weight, such as diethyl ether, methylethyl ether or dimethyl ether, and a minor proportion of a refined, light and relatively non-viscous lubricating oil,

preferably containing in addition a minute but sufilcientamount of an ether-antioxidant such as hydroquinone in order to prevent peroxide formation in storage. The ether content should be higher than 60% by volume and may be as high as 95% of the fluid; the content of the light lubricating or valve oil should not be below about 5% by volume and may approach but is preferably about 10% by volume of the fluid; the etherantioxidant may be present in from 0.05% to 0.5% of the whole admixture. The preferred composition of the invention is Per cent by volume Commercial ethyl ether Light valve oil 10 containing hydroquinone, 0.2% by weight, al-

I though these proportions may be varied within the limits indicated above.

The introduction of this fluid into the air intake stream of the engine, in accordance with the invention, may be accomplished by direct application to the'air entry port or through a short section of the intake pipe, arranged on a by-pass as desirable. Very preferably, it may be sprayed in mist form into the intake port, as with one o a few ejections from an ordinary device of tn; paint spray gun or fly spray type. Alternatively, it may be swept off the open end of a small di ameter pipe protruding through the wall of the air intake pipe, suitably fed from a storage chamber; or the fluid may be forced or poured onto a small mass of metal wool housed in a by-pass section of the intake pipe and, upon passage of the air through the by-pass at desired entry times, the liquid is carried into the combustion chamber in finely divided liquid spray form. In any case, the introduction of the cold starting fluid of the invention is stopped promptly upon the initiation of combustion of the hydrocarbon fuel normally introduced into the combustion chambers in the ordinary operations of the engine. f In exempliflcation of the compositions and tests are set forth in Table I. In these tests, a variable compression CF'R Motor Method Engine,

operated at 900 R. P. M., was employed under conditions to directly measure the compression ratio required for compression ignition and to indicate theminimum atmospheric temperature at which compression ignition would take place at a compression ratio of 16:1.

Table I Compression 4 ratio for or Example compression clorn mgr:

ignition R" 16:1

' 1 F. 1 Ethyl ether-{4025' valve 4. 91 --55 oll+0.2% hydroquluone. 2 Ethylctl1cr+l0% SAE30 5.00 52' automobile crankcase lubricating oil. 1 3- Ethyl ether+l% SAE 10 5.20 47 W automobile crankcase lubricating oil. I 4. Etlilyl cthcr+l0% valve 4. 91 -55 o 5 Ethyl ether-{40% cumcne; 5. 42 -41 6 Ethylcthcr+l0% xvlldlnc. 5.72 -33 7 Ethyl ethcr+0.2% hydro- 6. 00 62 quirione. 8 Ethyl ether 5.12 ;i9 9 Methyl ether 6. 62 -9 It will be observed that the minimum cold starting temperature is not only not significantly increased by the addition of minor amounts of a light lubricating oil such as the valve oil andthe SAE 10W' and SAE 30 oils included in the compositions of Examples 1, 2, 3 and 4, as would be expected, but that in most cases they actually lower the cold starting temperatures obtainable by the use of the ether alone. That remarkable result is indeed fortuitous, as repeated motor operations with fluids composed wholly or essentially wholly of the ether, in actual service at these temperatures, has shown that the presence of the light lubricating oil, of a volatility at least lower than that of the kerosenes and illuminating oils, is positively necessary in order to provide piston ring and cylinder wall lubrication during the starting operations, during which starting operations the normal crankcase lubricants are not effective to prevent scoring and wear. Moreover, the presence of the ether antioxidant augments rather than degrades the cold starting effect, both of the ether alone and of the ether containing minor proportions of light hydrocarbon lubricant.

By contrast, and for purposes of indicating the utility of the compositions of the invention, some .of which are exemplified by the data of Table I,

there are shown in Table II certain results obtained in operations identical to those above, on compositions other than those described and claimed-as a part of this invention.

In iurtherexempllfication of the compositions and methods of the inve'ntioma variable compression CER l-C engine was operated at 1200 R. P. M. under conditions to directly measure; the

compression ratio required for compression ignition and to indicate the minimum atmospheric pressure .at which compression. ignition would .take place at a compression ratio of 16:1. The

results of this series of operations are shown inTable III.

As heretofore noted, the presence of the light lubricating oil is necessary to the proper functioning oi the composition, and it will be seen that minor amounts thereof, with respect to the ether content, are not detrimental to the ability of the composition to perform its starting functions at very low temperatures. The refined light lubricating oil of petroleum distillate origin may advantageously be a cut or fraction of olefin polymer derivation such, for example, as the "light polymers" described in Holm, Lyman and Miller Patent No. 2,224,349, at lines 63-66 of column 2, page 6, and a composition comprising approximately by volume of commercial ethyl ether and approximately 10% by volume of such light polymers, containing from 0.05 to Light polymers, line 52: 7 Yield, gallons per hours 116 Gravity, A. P. I degrees 37.4-

Vlscosity' at 210 F 55 I claim:

1. A Diesel engine startingfluid adapted to initiate the operation of an internal combustion engine of the compression type at low temperatures, by compression alone, consisting essentially of an alkyl ether having at least two but less than five carbon atoms in the molecule in major proportion and a liquid hydrocarbon lubricant in an amount from about 5% to less than about 30% by volume based on the total volume of the starting fluid.

2. A Diesel engine startin fluid adapted to initiate the operation of aninternal combustion engine of the compression type at low temperatures; by compression alone, consisting essentially of more than 60% of an alkyl ether having at least two but'less than five carbon atoms in the molecule and a liquid hydrocarbon lubricant in an amount from about 5% to less than about 30% by volume based on the total volume of the engine of the compression type at low temperatures, by compression alone, consisting essentially of more than 60% of ethyl ether and from about The light- 5 5% to less than about 30% by volume based on the total volume of the fluid of a refined, light and relatively non-viscous liquid mineral oil lubricant, and containing an ether antioxidant in an amount suflicient to prevent peroxide formation.

4. A Diesel engine starting fluid adapted to initiate the operation or an internal combustion engine of the compression type at low temperatures, b compression alone, consisting essentially of more than 60% of ethyl ether and from about 5% toless than about 30% by volume based on the total volume of the fluid of volatile and relativel non-viscous liquid olefin polymers oi approximately 37.4 A. P. I. gravity and a viscosity index of approximately 55 at 210 F., and containin an etlier antioxidant in an amount suflicent to prevent peroxide formation.

5. A Diesel engine starting fluid adapted to initiate the operation of an internal combustion engine of the compression type at low temperatures, by compression alone, comprising about 90% commercial ethyl ether and about 10% by volume based on the total volume of the fluid of light hydrocarbon valve 011, and containing about 0.2% hydroquinone.

.R. WAYNE GOODALE.

6 REFERENCES CITED I The following references are of record in the file of this patent:

5 UNITED STATES PATENTS Number Name Date 1,105,016 Bassford 'July 28, 1914 1,325,907 Pettey et a1 Dec, 23, 1919 10 1,344,805 McAssey June 29, 1920 1,519,905 Kiboisiere Dec. 16, 1924 1,820,858 Huber Aug, 25, 1931 1,915,945 Nitardy June 27, 1933 1,969,202 Bugard Aug, 7, 1937 2,132,019 Evans Oct. 4, 1938 2,221,839 Lipkin Nov. 19, 1940 2,310,306 I Muller et al.- Feb. 9, 1943 2,364,356 Greathouse Dec. 28, 1944 FOREIGN PATENTS 20 Number Country Date 325,639 Great Britain Feb. 2'7, 1930 438,769 Great Britain Nov. 22, 1935 475,496 Great Britain Nov. 15, 1937 a 546,722 Great Britain Jul 28, 1942 479,175 France .L 1916 

